Glass-enclosed chamber and internal venetian blind having slats of improved reflectance and diffusivity over a wider spectral interval of incident solar radiation

Abstract

Inside a glass-enclosed chamber is a Venetian blind connected to internal elements for operating it, the elements being workable from outside to raise, lower and incline the slats. The raw slats of the blind are obtained by moulding a rolled strip of aluminium alloy hardened by magnesium. The strip has not been lapped in order to maintain a degree of roughness on both surfaces, ready to receive a reflecting layer. Reflective stratification includes a layer of pure aluminium adherent to the body of the slat that serves to fix a reflective type of interferential dielectric multilayer. Average thickness of the layer of sputtered aluminium depends on the diffusivity of reflected radiation required in relation to the maximum height of the peaks of surface roughness on the body of the slats. Useful multilayers increase reflectance to levels averaging over 85% on a wide interval of wavelengths from near infrared to ultraviolet.

Description

FIELD OF APPLICATION OF THE INVENTION[0001]The present invention concerns the technology for improving heat insulation in glass-enclosed chambers, and in particular a glass-enclosed chamber which contains a. Venetian blind having slats that possess greater reflectance and diffusivity over a wider spectral interval of incident solar radiation.REVIEW OF THE KNOWN ART[0002]Glass-enclosed chambers are usually of greater depth than the ordinary double glazing and can provide better screening against sun rays by the presence of hermetically-sealed internal means such as a Venetian blind, a roller blind or a pleated blind. Screening is graduated by operating the blind from outside. Glass-enclosed chambers with a Venetian blind inside offer a solution for effective control over the degree of brightness in daylight, especially where ventilation is controlled by centralized air conditioning, such as in trade fair buildings, exhibition halls, large stores, office blocks etc., and similarly on ...

AI Technical Summary

Benefits of technology

This patent is about a new glass-enclosed chamber for blinds that has several advantages. By sputtering a layer of pure aluminum onto the surface of the blinds, the chamber is coated with a reflective layer that helps reduce the amount of light that enters and causes misting. The resulting chamber is also more energy efficient and has improved insulation, reducing the need for air conditioning in the summer. Additionally, the manufacturing process is simplified and production costs are reduced.

Problems solved by technology

No improvement is obtained by the use of painted slats.

As glass-enclosed chambers are sealed, it is no easy matter to extract internal heat which by raising the inside temperature favours expulsion of heat through its walls.

If the metal slats become overheated, the blind becomes a source of undesired radiation that heats the other parts inside the chamber, such as cords, paint, motor, etc. adversely affecting the reliability of the product.

Once the temperature of these parts exceeds 60°, they may release vapours that condense on the cooler surfaces of the glass which then become fogged up.

This means that a single stratification is unable to reflect simultaneously and effectively on several spectral regions present in solar radiation.

A third reason is that, it is impossible to obtain all the layers in one layer-laying process only, whether applied by sputtering or by an equivalent method, this because of having to lay and reticulate the intermediate layer of silane or organic resin.

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